Just do it. My wife's brother didn't want us to be together because of my nationality and because of how sexy I am, but we still decided to be together and we are completely in love.
sit on it
Flip a coin
Sit on it
I'd give him the flick,if he hasn't got the *balls* to stand up to the family,he won't be much of a husband for you.
I think he wants to marry you not them,and spend the rest of his life with you,*Not them* So he has to decide one way or the other.